document.getElementsByTagName("html")[0].style.fontSize = screen.width * window.devicePixelRatio / 10 +"px";
var rto = 1 / window.devicePixelRatio ;
document.getElementById("vp").content = "width=device-width, initial-scale=" +rto+ ", minimum-scale=" +rto+ ", maximum-scale=" +rto+ ",user-scalable=no";